Mouse Acceleration Test
Move your mouse between the same two marks on your desk a few times slowly and a few times quickly. Without acceleration both give the same cursor travel; with acceleration the fast moves travel farther.
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| Run | Speed | Counts | Time | Avg speed | Source | Delete |
|---|---|---|---|---|---|---|
| No runs yet. | ||||||
How to use the Mouse Acceleration Test
- Pick two marks on your desk about 5 to 15 cm apart, for example the edge of a book and a coin. Use the same left edge of the mouse each time.
- Press Start test and allow the browser to hide the cursor.
- Slow runs: hold the left button, move slowly from the first mark to the second, release. Do this 3 times.
- Fast runs: the test switches to fast mode. Do the same move 3 times with a quick flick, stopping exactly on the mark.
- Read the verdict. Optionally switch to Raw input and repeat: raw runs should show no acceleration, which confirms the test.
How the acceleration check works
A mouse sensor reports movement in counts. Without acceleration, the operating system turns every count into the same cursor distance, so moving between two fixed marks always gives about the same total, whatever your speed. With acceleration the gain rises with speed, so a quick flick produces more counts on screen than a slow push.
The test averages your slow runs and your fast runs and reports ratio = average fast travel ÷ average slow travel. It only calls a difference real when it is larger than the run-to-run noise: the threshold is the bigger of 6% and twice the standard error, √(CVslow² ÷ nslow + CVfast² ÷ nfast), where CV is the coefficient of variation of each group.
Reading your result
| Ratio (fast ÷ slow) | Meaning | What to do |
|---|---|---|
| About 0.95 to 1.05 | No measurable acceleration: a 1:1 response | Nothing; ideal for consistent aim |
| Clearly above 1 (often 1.2 to 2+) | Pointer acceleration is on | Turn off Enhance pointer precision (Windows) or Pointer acceleration (macOS), or use raw input in games |
| Above 1 even in raw mode | Acceleration in mouse software or firmware, or uneven runs | Check the vendor app for "acceleration" or "angle snapping", then repeat carefully |
| Clearly below 1 | Negative acceleration: the sensor loses counts at speed | Change mouse pad, clean the sensor, test another mouse |
Tips for a clean measurement
- Use a physical stop such as a book edge for the end mark so you land in exactly the same spot each time.
- Make the fast runs genuinely fast: at least two to three times the average speed of the slow runs.
- Keep your wrist or arm motion the same and do not lift the mouse during a run.
- Compare System pointer and Raw input runs. Raw input skips OS speed and acceleration, so it is the reference a 1:1 setup should match.
- To find your sensor's true resolution, use the mouse DPI test after turning acceleration off.
Frequently asked questions
What is mouse acceleration?
Mouse acceleration (pointer acceleration) makes the cursor move farther when you move the mouse quickly than when you move it slowly over the same physical distance. Windows calls it Enhance pointer precision; macOS has it on by default and scales it with the tracking speed slider. It helps on large screens with small desks but makes aiming less consistent in games.
How does this test detect acceleration?
It counts the movement the browser reports during each run. If you cover the same physical distance, the count should be the same whatever your speed. The test compares the average count of fast runs with the average of slow runs: ratio = fast ÷ slow. A ratio clearly above 1 means acceleration; close to 1 means none.
What does the raw input option do?
In supported browsers (Chrome and Edge on Windows, macOS and ChromeOS) pointer lock can request unadjusted movement, which skips the operating system's acceleration and speed settings. A run in raw mode should show a ratio near 1.0, so it works as a control: if system mode shows acceleration but raw mode does not, the acceleration comes from the OS.
What is negative acceleration?
If fast runs travel noticeably less than slow ones, the sensor may be losing track at high speed, a problem called negative acceleration or malfunction speed. It is common with worn or cheap sensors, glossy or glass surfaces and dirty mouse feet or lenses. Try another mouse pad and clean the sensor.
How do I turn off mouse acceleration?
On Windows open Settings, Bluetooth and devices, Mouse, Additional mouse settings, Pointer Options and untick Enhance pointer precision. On macOS 14 and later go to System Settings, Mouse, Advanced and turn off Pointer acceleration. Many games also have a raw input option that bypasses it.
Why are my results inconsistent?
Hand placement matters: stop exactly on the mark and keep the same reference point on the mouse. A 2 mm miss on a 10 cm move is a 2% change. Do at least 3 runs of each speed and delete any where the mouse slipped. The test only reports acceleration when the difference is larger than your run-to-run variation.
Does this work with a trackpad?
Trackpads almost always use acceleration and do not have a fixed physical distance per count, so results are only a rough indication. The test is designed for a mouse.
Are all the tools on FreeToolCabin tested for quality and accuracy?
Yes! Every tool on our site undergoes automated Q/A testing in real browser environments to ensure high precision, correct output, and zero errors. If you happen to spot a bug or have a suggestion, please contact us at [email protected] and our team will review it right away.